Platforms/HiKey960Dxe: check whether reboot reason updated

Need to check whether reboot reason is updated. If it's updated,
avoid to clear the reboot reason since it's expected to be working
after reboot. If it's not updated, clear the reboot reason.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
1 file changed